Frequently Asked Questions

CSI Keyboards custom membrane switch FAQs

How do I request samples of your products?

To request product samples, please email us at sales@csikeyboards.com.

How do I request a quote?

You can easily request a quote by filling out our Quote Form, or by sending us an e-mail at sales@csikeyboards.com.
 
How long does it take you to quote a part?

It typically takes 1-3 days.
 
Do you provide prototypes?
 

Prototypes can be ordered with minimal cost to you. Please contact a CSI sales representative to discuss in greater detail.

What kind of artwork do you prefer to work with?

We prefer files created in vector format from programs such as Adobe Illustrator and CorelDraw.

How long will it take to get my parts?

This depends on a number of factors consisting of the complexity of the part, the thoroughness of the documentation we receive, the time taken to approve the CSI artwork proofs, and our factory capacity at the time you place your order. For a new design, our engineers will listen to your objectives and work together with you to determine the optimal switch construction to meet your functional and financial requirements. This initial design process and dialog is a critical step and can take some time. A general guideline for prototype/pilot runs is approximately 4-6 weeks after submission of the PO and satisfactory documentation. For production quantities a general guideline would be 4 weeks after approval of the prototype parts. As is always the case, under certain circumstances we may be able to accelerate those timelines. CSI will always do everything possible to meet your unique schedule requirements.

Can I spread out my production quantities so they are released to me over a period of time?

We make every effort to accommodate your scheduling needs to help you manage your inventory and increase your cash flow. While we evaluate each order on its own merits, in most situations we are more than willing to schedule your parts over the course of a year.

What is the best material to be used in a graphic overlay?

It all depends on the application. For membrane switch overlays we recommend polyester because of its chemical resistance and its ability to be last up to a million cycles prior to any sign of failure. Our polyester material is treated with a first surface hard coating that allows the overlay to survive in even the harshest environment.

What overlay thickness should I choose?

For excellent tactile feedback “feel” in a switch with stainless steel dome construction, choose an overlay thickness between .006″ and .008″. This thickness range will be durable enough to hold up to numerous switch cycles. A thicker overlay will significantly decrease tactile feedback (give a heavier feel).

How are the graphics printed?

We print the graphics with traditional screen printing or with our state of the art digital UV inkjet digital presses. If the application is for very high volume, the most cost effective way to print is screen printing. All graphics are printed on the second surface to protect the image.

What colors are available?

We can print just about any color or graphic image that can be designed. We typically use Pantone colors.

Can embossing improve the look and function of my overlay?

Depending on the design creativity, embossing can dramatically enhance the overall look of the graphic overlay. It can add to the function of the switch as well. Pillow emboss and rim emboss are the most popular methods.

What is the difference between silver flex circuits and copper flex circuitry?

Silver flex circuits were developed as a lower-cost option to copper flex circuits. Silver conductive ink is screen-printed onto a heat stabilized polyester film. Copper flex circuits begin with a solid copper film laminated onto a polyester or polyimide (Kapton) film that is then chemically etched away to leave copper traces. A silver flex circuit can be used with applications of 1 watt or less and has higher resistance than a copper flex circuit. A copper flex circuit can handle higher amps and voltage than a silver flex circuit and has lower resistance. Due to the low cost of the polyester base material and applying silver only where it is required, the silver flex is less expensive than Kapton copper flex. However a copper flex circuit may be more suitable for dense circuit arrays or in certain environmental conditions.

Can components be soldered onto the circuits?

Components can be soldered onto copper flex circuits. Components cannot be soldered onto silver flex circuitry and are attached with conductive adhesive.

What are the pitch constraints?

Copper flex allows a minimum of 0.5mm pitch. Silver flex allows a minimum of 1.0mm pitch.

What are the different methods of backlighting a membrane switch?

Please refer to our backlighting page.

What is the most highly recommended rear adhesive for your membrane switches?

In the majority of cases our membrane switches have 3M 467MP pressure sensitive adhesive as the rear adhesive layer. If your membrane switch is adhering to a much rougher surface we recommend 3M 468MP. If your membrane switch must adhere to a low surface energy material such as powder coated paint, we recommend the 3M 300-series adhesives such as 3M9471LE, 3M9472LE, 3M8132LE, and 3M8153LE adhesives.

Are there other adhesives available for specialty or extremely price sensitive applications?

There are many different adhesives designed for specialty applications. Our experienced design engineers will recommend the best adhesive option for your application.

What is the ideal application technique?

Bond strength is dependent on the amount of adhesive-to-surface contact developed. Firm application pressure develops better adhesive contact and thus improves bond strength. To obtain optimum adhesion, the bonding surfaces must be clean and dry. If alignment is a problem, we recommend beginning in the top corner and stick down a small amount of adhesive then remove the rest of the liner and work your way down applying pressure. This adhesive will take approximately 72 hours to fully cure from the time of initial bond. The ultimate bond strength will increase with time and temperature.

What are my connection options for the membrane switch tail?

The tail can be connected to a circuit board with several different connectors designed for flex circuits or it can be designed for use with a ZIF (Zero Insertion Force) connector. The most common is a female housing with a .100 (2.54mm) pitch. Other options include ZIF style, male housing and solder tabs.

What connectors does CSI have available?

Nicomatic is the most common with a female housing with straight pins. Other options include Amp, Molex and FCI connectors with latching housings, detent housings and reversible housings. Tin and gold plated contacts are also available.

Can you explain more about a ZIF (Zero Insertion Force) connection?

A ZIF is specified when space is critical in the design. The membrane switch tail has exposed contacts on the end. The tail is then inserted into the ZIF connector. The most commonly specified ZIF is a 1.00mm pitch. Other ZIF options are 2.54mm, 1.27mm and .50mm (copper etch)

What are your payment terms?

Our standard payment terms are Net 30.

Do you accept credit card payments?

Yes, we do accept credit card payments; however please note that there is a 4% service charge.

What type of warranty do you offer on your products?
 

For warranty information please contact our sales department.

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